Microcomposites of a rigid rod-like poly (p-hydroxy benzoic add ) (PHB) anda poly (butylene terephthalate) -- poly (tetramethylene glycol ) multiblock copolymer (PBT-- PTMG) were synthesize by in-- situ direct polycondensation. The effectof PHB contents and the concentrations of matrix polymer solution on themorphology and mechanical properties of the microcomposites obtained have been studied. The microcomposites prepared by in-- situ polycondensation exhibit much better uniform morphology and mechanical properties than those prepared by in-situ blend method.